Bootstrap Zero - Open-source, free Bootstrap templates collection.
Codespace - A beautiful cross-platform code snippet manager
Bootstrap Magic - Create your Bootstrap 4.0 themes easily with magic
CodeMyUI - Handpicked code snippets you can use in your web projects
Material Design for Bootstrap 4 - Powerful and free UI KIT for the newest Bootstrap 4 and Material Design
Creative Tim - Awesome Bootstrap freebies and templates to build better websites